<template>
  <div>
    <!-- 面包屑导航区域 -->
    <el-breadcrumb separator-class="el-icon-arrow-right">
      <el-breadcrumb-item :to="{ path: '/home' }">首页</el-breadcrumb-item>
      <el-breadcrumb-item>商品管理</el-breadcrumb-item>
      <el-breadcrumb-item>添加商品</el-breadcrumb-item>
    </el-breadcrumb>

    <!-- 卡片视图区域 -->
    <el-card>
      <!-- 提示区域 -->
      <el-alert
        title="添加商品信息"
        type="info"
        center
        show-icon
        :closable="false"
      ></el-alert>
      <!-- 步骤条区域 -->
      <el-steps
        :span="200"
        :active="activeIndex - 0"
        finish-status="success"
        align-center
      >
        <el-step title="基本信息"></el-step>
        <el-step title="商品参数"></el-step>
        <el-step title="商品属性"></el-step>
        <el-step title="商品图片"></el-step>
        <el-step title="商品内容"></el-step>
        <el-step title="完成"></el-step>
      </el-steps>
 
      <!-- tab栏区域-->
      <el-form
        :model="addForm"
        :rules="addFormRules"
        ref="addFormRef"
        label-width="100px"
        label-position="top"
      >
        <el-tabs v-model="activeIndex" :tab-position="'left'" :before-leave="beforeTabLeave" @tab-click="tabClicked">
          <el-tab-pane label="基本信息" name="0">
            <el-form-item label="商品名称" prop="goods_name">
              <el-input v-model="addForm.goods_name"></el-input>
            </el-form-item>
            <el-form-item label="商品价格" prop="goods_price">
              <el-input v-model="addForm.goods_price" type="number"></el-input>
            </el-form-item>
            <el-form-item label="商品重量" prop="goods_weight">
              <el-input v-model="addForm.goods_weight" type="number"></el-input>
            </el-form-item>
            <el-form-item label="商品数量" prop="goods_number">
              <el-input v-model="addForm.goods_number" type="number"></el-input>
            </el-form-item>
            <el-form-item label="商品分类" prop="goods_cat">
              <el-cascader
                expand-trigger="hover"
                v-model="addForm.goods_cat"
                :options="catelist"
                :props="cateProps" 
                @change="handleChange"
              ></el-cascader>
            </el-form-item>
          </el-tab-pane>

          <el-tab-pane label="商品参数" name="1">
            <!-- 渲染表单的item项 -->
            <el-form-item :label="item.attr_name" v-for="item in manyTableData" :key="item.attr_id">
              <el-checkbox-group v-model="item.attr_vals">
                <el-checkbox border :label="cb" v-for="(cb, i) in item.attr_vals" :key="i"></el-checkbox>
            </el-checkbox-group>
            </el-form-item>
          </el-tab-pane>

          <el-tab-pane label="商品属性" name="2">
            <el-form-item :label="item.attr_name" v-for="item in onlyTableData" :key="item.attr_id">
              <el-input v-model="item.attr_vals"></el-input>
            </el-form-item>
          </el-tab-pane>

          <el-tab-pane label="商品图片" name="3">
            <!-- action表示图片要上传到后台的api地址/headers表示为upload重新手动设置请求头 -->
            <el-upload
              action="http://127.0.0.1:8888/api/private/v1/upload"
              :on-preview="handlePreview"
              :on-remove="handleRemove"
              list-type="picture"
              :headers="headerObj"
              :on-success="handleSuccess">
              <el-button size="small" type="primary">点击上传</el-button>
              <div slot="tip" class="el-upload__tip">只能上传jpg/png文件，且不超过500kb</div>
            </el-upload>
          </el-tab-pane>

          <el-tab-pane label="商品内容" name="4">
            <!-- 富文本编辑器 -->
            <quill-editor v-model="addForm.goods_introduce"></quill-editor>
            <!-- 添加商品按钮 -->
            <el-button type="primary" class="btnAdd" @click="add">添加商品</el-button>
          </el-tab-pane>
        </el-tabs>
      </el-form>
    </el-card>

    <!-- 图片预览对话框 -->
    <el-dialog
      title="图片预览"
      :visible.sync="previewVisible"
      width="50%"
      >
      <img :src="previewPath" alt="" class="previewImg">
    </el-dialog>
  </div>
</template>  

<script>
import _ from 'lodash'

export default {
  data() {
    return {
      // 商品分类列表
      catelist: [],
      activeIndex: '0',
      // 添加商品的表单数据对象
      addForm: {
        goods_name: '',
        goods_price: '',
        goods_weight: '',
        goods_number: '',
        // 商品所属的分类数组
        goods_cat: [],
        // 图片的数组
        pics: [],
        // 商品的详情描述
        goods_introduce: '',
        attrs: []
      },
      addFormRules: {
        goods_name: [
          { required: true, message: '请输入商品名称', trigger: 'blur' },
        ],
        goods_price: [
          { required: true, message: '请输入商品价格', trigger: 'blur' },
        ],
        goods_weight: [
          { required: true, message: '请输入商品重量', trigger: 'blur' },
        ],
        goods_number: [
          { required: true, message: '请输入商品数量', trigger: 'blur' },
        ],
        goods_cat: [
          { required: true, message: '请选择商品分类', trigger: 'blur' },
        ]
      },
      // 级联选择器显示数据
      cateProps: {
        label: 'cat_name',
        value: 'cat_id',
        children: 'children'
      },
      // 动态参数列表
      manyTableData: [],
      // 静态属性列表
      onlyTableData: [],
      // 图片上传组件的headers请求头对象
      headerObj: {
        Authorization: window.sessionStorage.getItem('token')
      },
      previewPath: '',
      previewVisible: false
    }
  },
  created() {
    this.getCateList()
  },
  methods: {
    // 获取所有商品分类数据
    async getCateList() {
      const { data: res } = await this.$http.get('categories')
      if (res.meta.status !== 200) {
        return this.$message.error('获取商品分类数据失败')
      }
      this.$message.success(res.meta.msg)
      this.catelist = res.data
    },
    // 级联选择器选中项发生变化触发的函数
    handleChange() {
      // 判断是否为三级分类(只能选中三级)
      if(this.addForm.goods_cat.length !== 3) {
        this.addForm.goods_cat = []
      }
    },
    // 商品步骤的切换事件
    beforeTabLeave(activeName, oldActiveName) {
      if(oldActiveName === '0' && this.addForm.goods_cat.length !== 3) {
        this.$message.error('请选择商品分类')
        return false
      }
    },
    // 切换步骤后获取动态参数列表方法
    async tabClicked() {
      // 证明访问的是动态参数面板
      if( this.activeIndex === '1'){
        const {data: res} = await this.$http.get(`categories/${this.cateId}/attributes/`, {params: {sel: 'many'}})
        if (res.meta.status !== 200) {
          return this.$message.error('获取动态参数列表失败')
        }
        res.data.forEach(item => {
          item.attr_vals.length === 0 ? [] : item.attr_vals.split(' ')
        });
        this.manyTableData = res.data
      }else if(this.activeIndex === '2') {
        const {data: res} = await this.$http.get(`categories/${this.cateId}/attributes/`, {params: {sel: 'only'}})
        if (res.meta.status !== 200) {
          return this.$message.error('获取静态属性列表失败')
        }
        this.onlyTableData = res.data
      }
    },
    // 处理图片预览效果
    handlePreview(file) {
       this.previewPath = file.response.data.url
       this.previewVisible = true
    },
    // 处理图片移除操作
    handleRemove(file) {
      // 获取将要移除图片的临时路径
      const filePath = file.response.data.tmp_path
      // 调用splice方法从数组中删除Pics数组中相应的索引值
      const i = this.addForm.pics.findIndex(x => 
        x.pic === filePath
      )
      this.addForm.pics.splice(i, 1)
    },
    // 监听图片上传成功的事件
    handleSuccess(response) {
      // 拼接得到图片信息的对象
      const picInfo = { pics: response.data.tmp_path }
      // 将拼接结果push到pics中
      this.addForm.pics.push(picInfo)
    },
    // 点击按钮进行商品添加
    add() {
      // 1.进行表单预验证
      this.$refs.addFormRef.validate(async valid => {
        if (!valid) {
          return this.$message.error('请填写必要的表单信息')
        }
        // 2.执行添加商品的业务逻辑
        // 为了避免错误，对addForm→form进行深拷贝 lodash cloneDeep(obj)
        const form =  _.cloneDeep(this.addForm)
        form.goods_cat = form.goods_cat.join(',')
        // 处理动态参数和静态属性
        this.manyTableData.forEach(item => {
          const newInfo = {attr_id: item.attr_id, attr_value: item.attr_vals.join(' ')}
          this.addForm.attrs.push(newInfo)
        }),
        this.onlyTableData.forEach(item => {
          const newInfo = {attr_id: item.attr_id, attr_value: item.attr_vals}
          this.addForm.attrs.push(newInfo)
        })
        form.attrs = this.addForm.attrs
        const {data: res} = await this.$http.post('goods', form)
        if(res.meta.status !== 201) {
          return this.$message.error(res.meta.msg)
        }
        this.$message.success(res.meta.msg)
        this.$router.push('/goods')
      })
    }
  },
  computed: {
    cateId() {
      if(this.addForm.goods_cat.length === 3) {
        return this.addForm.goods_cat[2]
      }
      return null
    }
  }
}
</script>

<style lang="less" scoped>
.el-checkbox {
  margin-right: 5px;
}
.previewImg {
  width: 100%;
}
.btnAdd {
  margin: 15px 0;
}
</style>